Most gear motor quotations are slow because the enquiry was incomplete, not because the factory is slow. A supplier who receives “please quote your best price for a small gear motor, 100 units” has to guess at output speed, torque, duty, voltage and mounting before a model number can even be chosen. The guess becomes a follow-up question, the follow-up question becomes a day of email, and the buyer concludes that Chinese suppliers are unresponsive.
This guide is about the enquiry itself. It lists the eight fields that actually change what comes back on a compact AC gear motor quotation, explains how each one moves the price and the lead time, shows the three fields that most often force a re-quote, and ends with a copy-and-paste template. It is aimed at OEM buyers, machine builders and maintenance engineers who want a usable quotation in one exchange rather than three.
Technical completeness matters, but not every missing detail costs the same. The table below ranks the fields by how much they move the commercial answer. A quote that is missing the first four is not a quotation at all; it is an indicative price for a class of product.
| # | Field | What to write | What it changes in the quote |
|---|---|---|---|
| 1 | Kecepatan keluaran | rpm at the gearbox shaft, with the acceptable range | Fixes the gear ratio, and therefore the gearbox model and number of stages |
| 2 | Continuous torque | N·m at the output shaft, plus how you derived it | Fixes frame size and whether the ratio falls inside the allowable load table |
| 3 | Tugas | Running hours per day, starts per hour, reversing or not | Chooses between reversible and continuous-duty motor variants |
| 4 | Electrical supply | Voltage, phase, frequency | Fixes winding and run capacitor; determines whether the model exists for your market |
| 5 | Mounting and shaft | Foot or flange, shaft diameter, keyway, orientation, envelope limits | Chooses parallel-shaft or right-angle gearbox and the output configuration |
| 6 | Lingkungan | Ambient temperature, dust or water exposure, cleaning method | Enclosure and finish; may force a frame step up for thermal derating |
| 7 | Quantity | First order quantity and expected annual volume | Unit price tier, and whether the factory stocks or produces |
| 8 | Delivery terms | Target date, destination, Incoterm | Decides stock allocation versus production scheduling; affects the freight component |
Two of these deserve special emphasis because buyers routinely leave them out and then complain about the answer.
Quantity. In a factory that builds gear motors in batches, annual volume influences the unit price more than any single technical field. The same model, same ratio, same voltage can price very differently at 50 units and at 2,000 units per year, because the setup cost is amortised across the batch and because a volume commitment justifies a winding batch dedicated to your voltage. If you are at an early stage, say so and give an honest estimate rather than inflating it. Suppliers plan capacity on the number they were given, and a collapse from “10,000 per year” to 200 damages the relationship more than a modest number stated up front.
Duty. Duty determines the motor variant, and the variant is one of the few spec items that changes the price only slightly while changing the service life dramatically. A reversible motor with a 30-minute rating and a continuous-duty induction motor are often within a few percent of each other on price, so there is no commercial reason to accept the wrong one. The difference between them is explained in the reversible versus continuous-duty article.
The most common single error in a gear motor enquiry is quoting motor speed. “1450 rpm motor” describes the input side of a gearbox the buyer has not chosen yet, and it tells the supplier nothing about the machine.
Write the output speed and, if you only know a linear speed, give the pulley or sprocket diameter so the supplier can convert it:
Output speed from line speed:
n = v x 1000 / (pi x D) v in m/min, D in mm
Torque from a known force:
T = F x D / 2000 F in N, T in N.mThe same applies to torque. A number without a basis is a guess, and a supplier can either accept it or quietly use a different assumption. Stating the basis, even briefly, tells the supplier how much margin to apply. The torque calculation guide sets out the full chain from load to output torque, and the gear ratio guide covers the speed side.
Some omissions produce a question. Others produce a quotation that has to be redone, and a re-quote is where lead time is really lost. In practice three fields cause most of it.
| Field | What the supplier assumed | What changes when the truth arrives |
|---|---|---|
| Frequency, 50 or 60 Hz | 50 Hz because that is the domestic standard | Different rated speed and torque at 60 Hz, so a different ratio to hit the same output speed |
| Duty, reversible or continuous | Reversible, because it is the default small-frame variant | Different motor model, different price line, and a warning about continuous operation |
| Mounting orientation | Foot mounted, horizontal | A right-angle gearbox may be required, or a different orientation code, changing both price and envelope |
The frequency item catches buyers in export markets most often. On the same 90 mm frame, the 90W motor is rated 670 mN·m at 1350 rpm on 50 Hz and 544 mN·m at 1550 rpm on 60 Hz. If you need a specific output speed, the ratio that delivers it is not the same in both cases. The single-phase, three-phase and 50/60 Hz guide covers the selection logic.
Comparing quotations is where procurement effort pays off, and where it most often goes wrong. Two prices for “a 90W gear motor with a 30:1 ratio” can differ by 30 percent without either supplier being dishonest, because the scope is not the same.
Check these items line by line before comparing the numbers:
Ask each supplier to state the selected model, ratio, output speed, output torque, motor power, voltage and frequency, and lead time in a single block. A quote that cannot be reduced to those seven values cannot be compared technically, and price comparison without it is a comparison of assumptions. The OEM gearmotor buying guide takes this further into sample validation and the cost that does not appear on the quote.
Copy this into an email, fill in what you know, and mark the rest as “to confirm”. A good supplier will answer with a model recommendation and a list of the assumptions they made, which is exactly what you need to close the gaps.
Subject: RFQ - AC gear motor for [machine type], qty [n]
1. Application: [what the motor drives, one sentence]
2. Output speed: [x] rpm (line speed [v] m/min on [D] mm pulley)
3. Output torque: [x] N.m continuous / [x] N.m starting
Basis: [calculated / measured current / existing motor nameplate]
4. Duty: [x] hours per day, [x] starts per hour, reversing [yes/no]
5. Supply: [1-phase 220V 50Hz | 3-phase 380V 50Hz | ...]
6. Mounting: [foot / flange], shaft [d] mm, keyway [yes/no],
orientation [horizontal / vertical], envelope limit [WxHxL]
7. Environment: ambient [x] C, [dust / splash / washdown / clean]
8. Quantity: first order [n], annual [n]
9. Delivery: need by [date], destination [port/city], Incoterm [FOB/EXW/CIF]
10. Attachments: [drawing / photo / nameplate of existing unit]Field 10 is worth using even when everything else is complete. A photo of the existing unit with a ruler alongside the shaft, or a drawing of the mounting plate, resolves more ambiguity than three paragraphs of description. For a replacement order, the nameplate photograph alone often lets the supplier reconstruct most of fields 2 to 5.
A usable quotation comes back with a model number, a ratio, an output speed, a torque figure and a lead time. Read it in that order and check three things:
If the answer is a model you did not expect, that is not automatically a problem. Suppliers sometimes select a smaller frame at a lower ratio, or a larger frame at a higher ratio, to hit the same duty with better margin. What matters is that the output speed, output torque and duty all still match your requirement, and that the reasoning is visible.
An AC gear motor quotation becomes fast and accurate when the enquiry contains output speed, output torque with its basis, duty, electrical supply, mounting and shaft details, environment, quantity and delivery terms. Eight fields, most of them things the machine design already contains. The three that most often force a re-quote, frequency, duty variant and mounting orientation, are also the three that cost the least to confirm early.
Send the template above with whatever you have and mark the gaps. We would rather reply with a model recommendation plus a short list of assumptions than wait for a perfect enquiry, and you get a quotation you can compare line by line instead of a price that has to be taken on trust.
At minimum: output speed in rpm, continuous torque in N·m at the output shaft, duty cycle, voltage, phase and frequency, and mounting arrangement. Quantity and delivery terms then determine the commercial side. Anything you cannot supply can usually be estimated by the supplier if you describe what the motor has to drive.
Usually because the scope is different. Check whether the gearbox type matches, whether the ratio is a catalogue ratio or a special, what accessories are included, whether torque is quoted at rated speed or synchronous speed, and whether the price basis is ex-works or delivered. A like-for-like comparison requires the same model, ratio, torque and Incoterm on both sides.
Yes, with the gaps marked. Early quotations expose which part of the design is driving cost, usually the ratio or the voltage variant, while there is still time to change it. State clearly that the enquiry is preliminary so the supplier knows the numbers may move.
Give a realistic range and say it is an estimate. Factories plan capacity and price tiers on stated volume, and a very large number that does not materialise damages the relationship more than a modest, accurate one.
Commonly the run capacitor, output key, mounting bolts, cable and plug, and packaging beyond standard export cartons. Freight and insurance are excluded unless the price is quoted on a delivered basis. Ask for the inclusion list explicitly rather than assuming.
